Just posting this for the sake of completeness, there is now a new update to the principle guidelines, this replaces the last version (update 9) from early November.

For cancelled BA flights you can rebook for BA flights on the same route up to any date within ticket validity as long as there is space in the same cabin, you do not need same selling class availability. This also applies for reward bookings, so you do not need reward availability for the new flight, any selling class availability in the same cabin will do. This seems unaltered from the previous update. https://tradeuk.custhelp.com/app/ans...mer-guidelines



For those whose flights are are still operating, but are affected by a new entry requirement regulation, i.e documentation change or introduction to COVID-19 test, you are allowed to change to a later date, and options under BWC or FTV remain of course.